1. Field of the Invention
The present invention relates to a vertically aligned liquid crystal display and a manufacturing method thereof.
2. Discussion of the Background
Liquid crystal displays (LCDs) are one of the most widely used types of flat panel displays. An LCD has two display panels on which field generating electrodes, such as pixel electrodes and a common electrode, are disposed, and a liquid crystal (LC) layer disposed between the display panels. The LCD also includes a plurality of thin film transistors connected to the pixel electrodes, and a plurality of signal lines, such as data lines and gate lines, to apply voltages to the pixel electrodes by controlling the switching elements.
Among LCDs, a vertical alignment (VA) mode LCD, in which LC molecules are aligned such that their long axes are perpendicular to the panels in the absence of an electric field, is spotlighted because of its high contrast ratio and wide viewing angle.
In the VA mode LCD, the wide viewing angle may be realized by aligning an alignment layer through light irradiation so that the LC molecules have a pre-tilt angle.
To realize the wide viewing angle, the LC molecules should have pre-tilt angles in at least four directions such that the alignment layer is divided into four regions, and each region is irradiated. The light irradiation for each region is controlled with a shadow mask so that light is irradiated onto only a desired portion. However, the number of shadow masks and light irradiation processes increases as the number of regions increases, thereby complicating the manufacturing process.
Furthermore, because the LC molecules are pre-tilted relative to the surface of the substrate, light leakage may be generated in a black state of a normally black mode LCD such that the contrast ratio may be deteriorated.